The invention relates to a lubricant analyzer and in particular to an integrated lubricant analyzer which provides information about machine wear, lubricant contamination and lubricant chemistry and which provides predictive information with regard to surface degradation based on the analytical results.
Over the life of lubricated mechanical equipment, premature failure may occur for reasons other than reaching the end of the useful life of the equipment. Such premature failures may be the result of unexpected conditions such as mechanical accidents, power failures and the like. Such unexpected conditions account for a number of the causes of equipment failure. A more dominant cause of equipment failure, is premature failure as a result of surface degradation of the lubricated surfaces of interfacing parts. Surface degradation may be the result of corrosion of the surfaces caused by moisture or other contaminants in the lubricant or by wear caused by particles or solids in contact with the surfaces of the interfacing parts. Typically, corrosion accounts for about 20% of the surface degradation-based failures of equipment. Wear is believed to account for about 50% of the surface degradation-based failures of equipment.
Although industrial lubricating fluids are normally oils, either natural or synthetic, having some degree of lubricity, this is not true in every case. Water and solvent based fluids also have wide industrial utility as coolants or flushing fluids, for example. In industrial fluid systems such as hydraulic, lubrication, fuel and metal cutting process systems, it is essential to detect and measure the concentration of particulate contaminants entrained in the fluids. High levels of certain contaminants can dramatically decrease the efficiencies and life of machinery associated with the fluids.
Various laboratory methods exist for semiquantitative analysis of particulates and solids in such industrial fluids. For example, the silting index method of determining the degree of contamination is essentially a laboratory-oriented technique which provides a semiquantitative assessment of particulate contamination in the silt size range of between approximately 0.5 to 5.0 micrometers. In essence, this known method measures the decay in the rate of fluid flow resulting from the clogging of a membrane when a contaminated fluid sample is passed therethrough. Particles having a size greater than the pore size of the membrane are retained by the filter medium membrane. The silting index method is characterized by poor repeatability because particles which are much greater in size than the silt sized pores of the membrane form a loose, open filter cake, while particles having a smaller size than the pore size, or stable gels resulting from oxidation products and polymers, tend to block the pores of the membrane in an unpredictable manner.
Another known system for determining the level of contamination in a fluid utilizes the passing of the system fluid through a filter medium until a predetermined pressure drop is achieved across the filter medium. The level of contamination in the fluid is determined by measuring the time required to reach the predetermined pressure level. This method, therefore, has several problems. First, the known method is sensitive to the pressure level of the system upstream of the sensing filter medium, thereby requiring the use of an auxiliary pump to circulate a stream of the fluid at a constant pressure. This known system, therefore, produces a contamination indication which is subject to the effects of system flow rate, system pressure differential and fluid viscosity. Correction of the results produced by this system to compensate for such effects would require substantial additional cost.
Attempts have been made to provide analytical equipment which may be used to determine the root causes of equipment failure. Such equipment has been limited to monitoring or analysis of a single parameter or characteristic of the lubricant once the most dominant cause of equipment failure has been identified. The determination of multiple properties of lubricating fluids requires multiple stand-alone instruments. There exists a need for an integrated lubricant analyzer which has the ability to monitor and predict equipment failure based on corrosion and wear with the ability to identify the primary source or sources of wear of the lubricated surfaces.
With regard to the above and other objects and advantages thereof, the invention provides an integrated lubricant analyzer apparatus. The apparatus includes a housing having a first fluid inlet port in flow communication with a chemical analysis device for chemical analysis of fluid communicated to the chemical analysis device via the first fluid inlet port. Analysis of a fluid sample inserted in the first fluid inlet port provides chemical data corresponding to chemical properties of the fluid communicated to the chemical analysis device. A second fluid inlet port is included in the housing in flow communication with a particle analyzer for providing particle identification data corresponding to particle properties of fluid communicated to the particle analyzer via the second fluid inlet port. The housing also includes a third fluid inlet port in flow communication with an optical particle counting device for providing particle count data corresponding to particle properties of fluid communicated to the particle counting device via the third inlet port. A syringe degassing port is attached to the housing for inverting and degassing a syringe containing a fluid sample for particle count analysis before the fluid sample is injected into the third fluid inlet port. An automatic sample injection device for injecting a fluid sample through the third fluid inlet port. The apparatus includes a sample analysis sequencing procedure for sequential analysis of the fluid samples. A microprocessor is contained within the housing for collection and manipulation of data from the chemical analysis device, the particle analyzer and the particle counting device for providing an output to a user indicating corrective action required based on the sample data.
In another aspect the invention provides a method for analyzing a lubricant sample for corrosive and abrasive components using the above described lubricant analysis device. According to the method, a lubricant sample to be analyzed is collected and a first portion of the sample is injected into the first fluid inlet port. A second portion of the sample is deposited in the second fluid inlet port. A third portion of the sample is degassed and injected into the third fluid inlet port. Analysis is collected on each of the samples providing chemical analysis data, particle identification data and particle count data and an output is provided by the device to a user indicating corrective action to be taken based on the data. In yet another aspect the invention provides a lubricant analyzer apparatus including a fluid inlet port for a lubricant sample, a sample syringe containing a plunger for injecting the lubricant sample into the fluid inlet port and a syringe degassing device for removing entrained and dissolved gases from the lubricant sample prior to injecting the sample into the inlet port. The degassing device is provided with a syringe adapter for connecting the syringe in an inverted orientation thereto for degassing a fluid sample in the syringe. The degassed sample is injected into the fluid inlet port at a predetermined rate using a linear motion-controlled arm attached to the syringe plunger. A particle counting device in flow communication with the fluid inlet port provides particle count data respective of particle contamination of the lubricant sample.
Yet another aspect of the invention provides an integrated lubricant analysis device which includes a housing containing at least three fluid analysis devices in electronic communication with a microprocessor for manipulation of data obtained from the fluid analysis devices. A series of light emitting diodes provide indication to a user of a predetermined analysis sequence. The analysis device includes a selector switch having positions corresponding to the predetermined analysis sequence for selecting an analysis device sample analysis and for input of data to the microprocessor, the position of the selector switch being selected by the user in response to activation of one or more of the light emitting diodes by the microprocessor.
The apparatus of the invention provides a substantially completely integrated analytical device which may be used to monitor and predict the cause or causes of equipment failure based on a trivector analysis of an oleaginous fluid. The term xe2x80x9ctrivector analysisxe2x80x9d refers to a unique system in which the severity of changes in lubricant chemistry, machine wear and contamination is plotted on a three-spoke spider chart. This plot provides a quick overall view of the lubricant and machine so that maintenance technicians spend less time interpreting numerical data in a spreadsheet. An unique feature of the invention is that the apparatus provides integrated analysis of lubricant chemistry, machine wear and contamination in a single integrated instrument. Another unique feature of the invention is that the apparatus provides a means for obtaining a more accurate particle count than other particle count instruments as a result of a degassing apparatus and procedure included in the apparatus. It will be recognized that the term xe2x80x9cparticlexe2x80x9d, as used herein, is not intended to be limited to solid materials but also includes fluid or liquid materials which are immiscible in oil such as water droplets.